1. Field of the Invention
The present invention relates generally to loading and unloading mechanisms for a data storage cartridge, as well as data drives comprising such mechanisms.
2. Related Art
Data storage cartridges have been used to house removable data storage media. The cartridge typically comprises a housing that serves as a protective enclosure for a disk medium. In the past, this disk medium has been in the form of a magneto-optical (MO) disk medium. However, another type of data storage system, known as holographic storage, is described in, for example, U.S. Pat. No. 5,719,691 (Curtis et al.), issued Feb. 17, 1998, and U.S. Pat. No. 6,191,875 (Curtis et al.), issued Feb. 20, 2001. It may be desirable that the holographic data storage (HDS) medium be provided in a disk form and housed in a cartridge similar to those used for an MO disk medium. This enables HDS manufacturers to utilize existing MO cartridge designs and handling mechanisms for easy conversion to HDS applications. See, for example, commonly assigned U.S. Patent Application 2005/0028185 (Hertrich), published Feb. 5, 2005 and U.S. Patent Application 2005/0028186 (Hertrich), published Feb. 5, 2005, the entire disclosure and contents of which are incorporated by reference, for some illustrative data storage cartridges for holographic disk media.
These removable data storage cartridges may comprise a disk-shaped data storage medium having a rotatable hub provided or attached at the center of the disk medium, and are inserted into data storage drives that can read data from and write data to such removable data cartridges. Some data storage drives include a “soft load” mechanism, which receives a data cartridge inserted into a load port of the drive, and translates the cartridge to couple the hub in the data cartridge with a spindle mechanism in the drive. The loading mechanism often translates the cartridge first in a lateral direction to draw the cartridge fully into the drive, and then in a downward direction to lower the cartridge onto the stationary drive spindle. After coupling, the drive spindle rotates the data storage disk medium (typically circular shaped) past a radially positionable read/write head, which may read data from and/or write data to various locations on the data storage medium.
In a conventional HDS drive system, the HDS cartridge is inserted through the drive door of the data drive. After insertion, a sensor is often triggered to indicate that the HDS cartridge may be loaded onto the drive spindle. The mechanism for loading (as well as unloading) the cartridge onto the drive spindle is typically powered by one motor with the proper gear reduction necessary to overcome the forces required for either loading or unloading the cartridge. Another separate motor is then typically used to move or transport the loaded cartridge underneath a stationary optical head assembly used to write and/or read data from the disk medium within the HDS cartridge. This transporting/loading process is then reversed to unload or eject the HDS cartridge from the data drive.
At some point during the loading of the HDS cartridge and transportation underneath the optical head assembly, a shutter associated with the cartridge may be opened to expose the disk medium for writing and/or reading of data by the optical head assembly. For HDS cartridges, it is important that the loading/unloading mechanism for the cartridge operate in a manner such that the drive door of the data drive is fully closed before this shutter is opened. In addition, the loading/unloading mechanism for the HDS cartridge should desirably fit within the standard configuration for a data drive, which is typically a width of no more than about 5.75 inches (14.61 cm.) and a height of no more than about 3.25 inches (8.26 cm). Further, the cartridge loading/unloading mechanism should provide for reliable operation, as well as ease of assembly.